Sound barriers and walls are commonly constructed using concrete panels. The concrete panels are manufactured in relatively large quantities at off-site locations, and transported to a site for constructing the sound barriers or walls. For aesthetic reasons, the concrete panels are typically colored, and in many cases are textured. The textures may include simple design patterns or elaborate designs, such as mosaics of landscapes (e.g., mountains, desert), animals or other artistic designs. In some cases, the textures also have functional purposes, such as to help aid in noise reduction.
Molds and stamps that include a negative of the desired texture are used to apply the textures to the panels. During the manufacture of the panels, concrete, or an alternative pliable material is poured into a mold that has a negative of the desired texture. When the concrete sets, it will include an imprint of the texture from the mold. A stamp is used to apply a texture to the top side of the panel, if desired. When the concrete (or other pliable material) has reached a specific viscosity, a stamp with the desired texture is placed in contact with the top side of the concrete panel, and force is applied to the stamp to imprint the texture onto the concrete panel.
U.S. Pat. No. 5,202,132 to Myers et al. ('132 patent) describes a method and device for stamping a texture on concrete panels. The '132 patent describes the use of a curved (convex) face that includes a texture for applying a design to a concrete panel. The curved face is moved in a rocking motion to apply the texture to the concrete panel. The rocking motion requires the design of a complicated hydraulic system to attempt to uniformly apply pressure to the curved face during the rocking motion. The device must have vertical stops readjusted for each height of concrete panel being manufactured, because of variations in panel height or screed height. If the stops are not adjusted properly, or the screed height is not correct, a pattern will not be fully imprinted, or the pattern will smear. If the rigid curved face has a positive or negative camber in the cross direction or if the concrete is not flat, the print will not be uniform. Additionally, the hydraulic system must be maintained and adjusted properly or the texture design applied to the panel will not be uniform, i.e., light in some areas and heavy in others. It is very difficult to trouble shoot hydraulic or mechanical problems with this complicated device. Moreover, because the prior art face is curved, vibration on the table or the stamp face will cause the pattern to slump in the non-contact areas resulting in reduced quality of the imprinted texture.
Accordingly, a need exists for applying a texture to a pliable surface, such as a surface of a concrete panel, which eliminates the problems encountered with the conventional approach to applying textures, and which improves the quality of the final imprinted design.